Sort printed maps in test output (#917)

Author: sashton

CHANGELOG.md

@@ -21,6 +21,7 @@
 * [#913](https://github.com/clojure-emacs/cider-nrepl/pull/913): Disable background warmup of `orchard.java` cache.
 * [#913](https://github.com/clojure-emacs/cider-nrepl/pull/913): Enable background warmup of Compliment cache.
 * [#914](https://github.com/clojure-emacs/cider-nrepl/pull/914): Remove javadoc section from the inspector output.
+* [#917](https://github.com/clojure-emacs/cider-nrepl/pull/917): Sort printed maps in test output
 
 ## 0.52.1 (2025-02-24)
 

src/cider/nrepl/middleware/test.clj

@@ -72,6 +72,24 @@
                  %))
             analyzed-trace))))
 
+(defn deep-sorted-maps
+  "Recursively converts all nested maps to sorted maps."
+  [m]
+  (try
+    (walk/postwalk
+     (fn [x]
+       (if (map? x)
+         (with-meta (into (sorted-map) x) (meta x))
+         x))
+     m)
+    (catch Exception _
+      ;; Maps with non-comparable keys aren't sortable so they should be returned as-is.
+      ;; Examples:
+      ;;   {{} 1}
+      ;;   {1 1 :a 1}
+      ;;   {"a" 1 :a 1}
+      m)))
+
 (defn- print-object
   "Print `object` using println for matcher-combinators results and pprint
    otherwise. The matcher-combinators library uses a custom print-method
@@ -83,7 +101,8 @@
         print-fn (if matcher-combinators-result?
                    println
                    pp/pprint)
-        result (with-out-str (print-fn object))]
+        ;; The output will contain sorted maps for better readability and diff comparisons.
+        result (with-out-str (print-fn (deep-sorted-maps object)))]
     ;; Replace extra newlines at the end, as sometimes returned by matchers-combinators:
     (str/replace result #"\n\n+$" "\n")))
 

test/clj/cider/nrepl/middleware/test_test.clj

@@ -209,7 +209,10 @@
         "pprint is chosen, as indicated by quoted strings and newlines")
     (is (= "{:a \"b\", :c \"42\"}\n"
            (#'test/print-object (with-meta {:a "b" :c "42"} {:type ::mismatch})))
-        "pprint is chosen, because :type does not match matchers-combinators keyword")))
+        "pprint is chosen, because :type does not match matchers-combinators keyword"))
+  (testing "maps are printed with sorted keys"
+    (is (= "{:a 1, :b 2, :c 3, :d {x 1, y 2, z 3}}\n"
+           (#'test/print-object {:b 2 :c 3 :a 1 :d {'z 3 'y 2 'x 1}})))))
 
 (deftest test-result-test
   (testing "It passes `:error`s to `test/*test-error-handler*`"